A vast assortment of signaling lights, including search and rescue devices for the use on vessels in distress, have been used for many years. The use of pyrotechnic flares has been in the past the most commonly used for distress signal devices. Pyrotechnic flares are exceptionally dangerous because they can easily burn the people using them, they can start the vessels on fire if there is a fuel leak and they can even burn under water creating additional problems. Moreover, one cannot overemphasize the potential environmental disaster of flare disposal. Over the next three years it is estimated that approximately 30 million flares will be disposed of improperly or illegally.
The Coast Guard's Research, Development, Test and Evaluation (RDT&E) program is working on more than 80 projects that support Coast Guard requirements across all mission areas. The RDT&E program is comprised of the Office of RDT&E at Coast Guard Headquarters in Washington, D.C., and the Research and Development Center (RDC) at New London, Conn. The RDC is the Coast Guard's sole facility performing applied RDT&E experimentation and demonstrations.
The RDT&E program pursues technologies that provide incremental improvements as well as those with the greatest potential to strategically transform the way the Coast Guard does business.
The RDT&E program leverages partnerships with academia, other government agencies and private industry, to proactively anticipate and research solutions to future technological challenges.
Search and Rescue Distress Notification Methods and Alternatives by the United States Coast Guard reviewed pyrotechnic flares that are commonly used by mariners to signal distress. Flares have drawbacks and present significant storage and disposal problems. The RDC was sought to determine appropriate criteria to evaluate light emitting diode (LED) or other light signals as potential maritime distress signals.
The project team selected a group of LED, flashtube (strobe) and incandescent-based devices to obtain photometric data. An understanding of the physical and perceptual aspects of these devices allowed the project team to select a subset of devices for further evaluation.
Following the lab tests, the project team designed and conducted two field demonstrations. The first demonstration assessed individual devices to determine the most effective signal characteristics based on detectable range, ability to attract attention and ability to distinguish the signal against background lighting. A second demonstration used a subset of the devices to compare the most effective characteristics, head-to-head. Finally, a separate evaluation looked at device ergonomics to help understand the physical aspects of the devices that would make them easier to use.
This project was to determine suitability of potential alternatives to pyrotechnic visual distress signals by.
Evaluating the effectiveness of presently available LED (and other) devices as Visual Distress Signal Devices.
Reviewing functional requirements for visual distress signals.
Investigating and reporting on device characteristics and evaluating them against existing pyrotechnic standards.
Investigating and reporting on “experimental” or “developmental” technologies and evaluating them against pyrotechnic standards.
Determining the most effective light-signal characteristics for alternative Visual Distress Signal Devices.
Additionally, this project will produce recommendations for future non-pyrotechnic requirements and applications. Recommendations will address the feasibility of whether non-pyrotechnic devices could replace pyrotechnics as alert, locate and/or marker devices. Alert and locate specifications for the signal lights differ in the varying peak intensity and the focal height of the LED emitted light, which can be altered by manually adjusting the distance between the LED and the optics.
Numerous innovations for the Visual Distress Signal Device have been provided in the prior art that are described as follows. Even though these innovations may be suitable for the specific individual purposes to which they address, they differ from the present design as hereinafter contrasted.
The following is a summary of those prior art patents most relevant to this application at hand, as well as a description outlining the difference between the features of the Visual Distress Signal Device and the prior art.
U.S. Pat. No. 7,153,002 of Jin Jong Kim describes a lens for light emitting diode (LED) light sources which allows light emitted from an LED light source to exit the lens in a direction perpendicular to a vertical center axis of the lens. The lens of the present invention includes an inner space which is defined in a lens body having both a bottom surface and an upper reflective surface, so that light passing through the inner space is partially reflected by total internal reflection on a portion (selective transmission surface, inner reflective surface, inside reflective surface) of a boundary surface between the inner space and the lens body. Thus, light emitted from an LED light source efficiently exits the lens through a side surface. Accordingly, the lens of the present invention is used in efficient display and illumination of optical systems.
This patent describes a light emitting diode (LED) light sources which allows light emitted from an LED light source to exit the lens in a direction perpendicular to a vertical center axis of the lens used in display and illumination optical systems. This lens does not have the same internal structure and it only describes LED light source exiting the lens in a direction perpendicular to a vertical center axis of the lens. It does not address the value of a portion of the light to be directed vertically or describe the other unique features of the Visual Distress Signal Device.
U.S. Pat. No. 6,679,621 of Robert S. West et al. describes a lens that comprises a bottom surface, a reflecting surface, a first refracting surface obliquely angled with respect to a central axis of the lens, and a second refracting surface extending as a smooth curve from the bottom surface to the first refracting surface. Light entering the lens through the bottom surface and directly incident on the reflecting surface is reflected from the reflecting surface to the first refracting surface and refracted by the first refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens. Light entering the lens through the bottom surface and directly incident on the second refracting surface is refracted by the second refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens. The lens may be advantageously employed with LEDs, for example, to provide side-emitting light-emitting devices. A lens cap attachable to a lens is also provided.
This patent describes a side-emitting light-emitting lens that does not have the same internal structure and again does not address the value of a portion of the light to be directed vertically or describe the other unique features of the Visual Distress Signal Device.
U.S. Pat. No. 6,607,286 of Robert S. West et al. describes a lens mounted to a light emitting diode package internally redirects light within the lens so that a majority of light is emitted from the lens approximately perpendicular to a package axis of the light emitting diode package. In one embodiment, the light emitted by the light emitting diode package is refracted by a saw tooth portion of the lens and reflected by a total internal reflection portion of the lens.
This patent describes another side-emitting light-emitting lens that does not have the same internal structure and again does not address the value of a portion of the light to be directed vertically or describe the other unique features of the Visual Distress Signal Device.
U.S. Pat. No. 6,598,998 of Robert S. West et al. describes a lens mounted to a light emitting diode package internally redirects light within the lens so that a majority of light is emitted from the lens approximately perpendicular to a package axis of the light emitting diode package. In one embodiment, the light emitted by the light emitting diode package is refracted by a saw tooth portion of the lens and reflected by a total internal reflection portion of the lens.
This patent describes another side-emitting light-emitting lens that does not have the same internal structure and again does not address the value of a portion of the light to be directed vertically or describe the other unique features of the Visual Distress Signal Device.
U.S. Pat. No. 2,492,837 of Eugene Briggs describes an electronically operated signal lights and more particularly to a portable light of the flashing type adapted for emergency or signal use.
This patent describes a self-contained portable flashing light of the gaseous discharge type energized by a battery that has not been designed to be used in a marine environment and does not float in the water.
U.S. Pat. No. 5,034,847 of John E. Brain describes a portable light beacon for use on life rafts and the like that has a long life due to a flashing light allowing the battery to recharge and a water sensing switch that once wet remains on. The light beacon comprises a portable battery power source in a water proof container, a flashing light with watertight electrical connections between the flashing light and the power source, and a fluid sensing switch comprising a fluid absorbent composition positioned between two terminals with circuitry to activate the flashing light when an electrical conductive fluid has been absorbed by the fluid absorbent composition to provide an electrical path between the two terminals.
This patent describes a hand held light beacon for use on life rafts and the like that has a long life due to a flashing light but does not have the lens capability of horizontal or vertical light directing and has not been designed to float vertically or be tied by a lanyard lifted to the top of a mast.
U.S. Pat. No. 7,182,479 of John f. Flood et al. describes a portable, hand-held, electrically powered, high intensity directed light beam generating device for use as a replacement for a pyrotechnic flare for search and rescue, especially in a marine environment. The light intensity is generated by a xenon strobe flash tube in a covered, mirror reflective housing that allows for a directional beam of light of less than 6 steradians. The limited radiation light direction provides a safe optical solution for the user to prevent eye damage while increasing the beam intensity and range. The light and illumination section surrounding the strobe flash tube includes thermally conductive paths for the heat generated by the flash tube to be transmitted to the outside of the housing.
This patent describes a hand held electrically powered, high intensity directed light beam generating device but does not have the unique lens capability nor does it float in the water and if you let go of it would sink.
U.S. Pat. No. 7,703,950 of Jurgen E. Ewert et al. describes a side-emitting lens for use with an LED lamp provides a distribution of emitted light that is substantially normal to an axis of symmetry of the lens; the light can also be symmetrical with respect to a plane normal to the lens axis. The lens has a cavity in which the LED lamp can reside, having a cavity refracting surface with a central section and a stepped cavity sidewall. The lens also has a base external refracting surface surrounding the cavity, an internal reflecting surface spaced apart from the cavity, and a side surface; these surfaces redirect light that enters the lens through the cavity refracting surface. For many applications, the lens axis is vertical in service and the lens is configured to provide a narrow distribution of light in the horizontal plane.
This patent describes only a side-emitting lens for an LED lamp having a base section with a cavity defined by a cavity refracting surface with a substantially planar central section, which is substantially normal to the central lens axis, and a stepped cavity sidewall having a series of sidewall refracting surfaces, and a base external refracting surface symmetrically disposed about the central lens axis and spaced apart from said stepped cavity sidewall. The Visual Distress Signal Device lens does not have the stepped cavity sidewall but has a concave inner surface while having drain capability of the conical upper cavity. The application additionally provides the complete structure of the Visual Distress Signal Device and its unique floating capabilities.
U.S. Pat. No. 8,702,256 of Hans Poul Alkaer relates to an emergency light device for marine use comprising a housing accommodating an electronic circuit, at least one transparent dome, and a first and a second housing member, said electronic circuit comprising at least one light emitting diode provided in the one transparent dome, an electrical power supply comprising at least one battery of the AA, AAA or AAAA type, and at least one operating switch, said emergency light characterized in that the housing has a width which is substantially larger than the height, preferably the width is at least double or triple the height.
This patent describes a light for a life jacket that would sink if it were dropped in the water and does not provides the complete structure of the Visual Distress Signal Device and its unique floating capabilities.
U.S. Pat. No. 6,805,467 of Edward A. Wolf describes a portable emergency light for long range detection by flight and marine search and rescue personnel which utilizes a battery-powered laser array mounted and sealed within a waterproof housing to increase the effective intensity of a specific class laser. The laser array includes a plurality of laser light generators mounted together to project substantially along a common optical axis producing a signaling light. The search and rescue light may include a rotatable head for directing the signaling lights along a 360 degree plane and a three-dimensional gimbal which maintains the light beams in a level horizontal position so that the signaling lights may be easily projected along the entire horizon relative to the user. Each laser light generator is within US Government safety standards for the specific class laser despite the increased power of the signal. The laser array can be used with optical alignment lenses to form a desired highly visible light pattern.
This patent describes an emergency laser array signal light that utilizes a battery-powered laser array mounted and sealed within a waterproof housing to increase the effective intensity of a specific class laser but does not have any floating capability.
In this respect, before explaining at least one embodiment of the Visual Distress Signal Device in detail it is to be understood that the design is not limited in its application to the details of construction and to the arrangement, of the components set forth in the following description or illustrated in the drawings. The Visual Distress Signal Device is capable of other embodiments and of being practiced and carried out in various ways. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.